1. Technical Field
The present invention relates to a seat belt system having an inflatable seat belt portion. In particular, the present invention relates to a tongue assembly and a buckle for use in such a seat belt system.
2. Description of the Prior Art
Inflatable seat belts are known. An inflatable seat belt is inflated by inflation fluid from an inflation fluid source. The inflation fluid is typically passed through one or more conduits to an inflatable portion of the seat belt, normally the torso portion, to inflate the inflatable portion.
The seat belt is typically a part of a seat belt system that includes a tongue assembly engageable with a buckle. The prior art shows various mechanisms for passing inflation fluid through, or past, the connection between the tongue assembly and the buckle.
The present invention is a seat belt system for helping to protect an occupant of a vehicle seat. The system comprises a seat belt, a tongue assembly through which the seat belt extends, and a buckle. The buckle is engageable with the tongue assembly to secure the seat belt system in a buckled condition in which the seat belt is divided by the tongue assembly into a torso portion that extends across the torso of the occupant and a lap portion that extends across the lap of the occupant. The seat belt system also includes an inflatable device comprising an inflatable portion of the seat belt. An inflation fluid source provides inflation fluid to the inflatable device only when the tongue assembly is engaged with the buckle. The system also includes a cinch mechanism having a cinched condition for resisting movement of the seat belt through the tongue assembly when the tongue assembly is engaged or disengaged with the buckle. The cinch mechanism also has a released condition. The inflatable device, when inflated, causes the cinch mechanism to move from the cinched condition to the released condition and causes the torso portion and the lap portion of the seat belt to be tensioned about the vehicle occupant.